Xinput.xml (47341B)
1 <?xml version="1.0" encoding="UTF-8" ?> 2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" 3 "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd"[ 4 <!ENTITY % defs SYSTEM "/xserver/doc/xml/xserver.ent"> %defs; 5 ]> 6 7 <!-- lifted from troff+ms+XMan by doclifter --> 8 <book id="porting"> 9 10 <bookinfo> 11 <title>X11 Input Extension Porting Document</title> 12 <authorgroup> 13 <author> 14 <firstname>George</firstname><surname>Sachs</surname> 15 <affiliation><orgname>Hewlett-Packard</orgname></affiliation> 16 </author> 17 </authorgroup> 18 <releaseinfo>X Server Version &xserver.version;</releaseinfo> 19 <copyright><year>1989</year><year>1990</year><year>1991</year> 20 <holder>Hewlett-Packard Company</holder> 21 </copyright> 22 23 <legalnotice> 24 25 26 <para> 27 Permission to use, copy, modify, and distribute this documentation for any purpose and without fee is 28 hereby granted, provided that the above copyright notice and this permission notice appear in all copies. 29 Hewlett-Packard makes no representations about the suitability for any purpose of the information in this 30 document. It is provided "as is" without express or implied warranty. This document is only a draft stan- 31 dard of the X Consortium and is therefore subject to change. 32 </para> 33 </legalnotice> 34 35 <legalnotice> 36 <para role="multiLicensing">Copyright © 1989, 1990, 1991 X Consortium</para> 37 <para>Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:</para> 38 <para>The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.</para> 39 40 <para>THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.</para> 41 42 <para>Except as contained in this notice, the name of the X Consortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium.</para> 43 44 <para>X Window System is a trademark of The Open Group.</para> 45 </legalnotice> 46 47 </bookinfo> 48 49 <chapter id="x11_input_extension_porting_document"> 50 <title>X11 Input Extension Porting Document</title> 51 52 <para> 53 This document is intended to aid the process of integrating the 54 X11 Input Extension into an X server. 55 </para> 56 <para> 57 <!-- .LP --> 58 Most of the functionality provided by the input extension is 59 device- and implementation-independent, and should require no changes. 60 The functionality is implemented by 61 routines that typically reside in the server source tree directory 62 extensions/server/xinput. 63 This extension includes functions to enable and disable input extension devices, 64 select input, grab and focus those devices, query and change key 65 and button mappings, and others. The only input extension requirements 66 for the device-dependent part of X are that the input devices be 67 correctly initialized and input events from those devices be correctly 68 generated. Device-dependent X is responsible for reading input data from 69 the input device hardware and if necessary, reformatting it into X events. 70 </para> 71 <para> 72 <!-- .LP --> 73 The process of initializing input extension devices is similar to that used 74 for the core devices, and is described in the following sections. When 75 multiple input devices are attached to X server, the choice of which devices 76 to initially use as the core X pointer and keyboard is left 77 implementation-dependent. It is also up to each implementation to decide 78 whether all input devices will be opened by the server during its 79 initialization and kept open for the life of the server. The alternative is 80 to open only the X keyboard and X pointer during server initialization, and 81 open other input devices only when requested by a client to do so. Either 82 type of implementation is supported by the input extension. 83 </para> 84 <para> 85 <!-- .LP --> 86 Input extension events generated by the X server use the same 32-byte xEvent 87 wire event as do core input events. However, additional information must be 88 sent for input extension devices, requiring that multiple xEvents be generated 89 each time data is received from an input extension device. These xEvents are 90 combined into a single client XEvent by the input extension library. A later 91 section of this document describes the format and generation of input extension 92 events. 93 </para> 94 <sect1 id="Initializing_Extension_Devices"> 95 <title>Initializing Extension Devices</title> 96 <para> 97 <!-- .LP --> 98 Extension input devices are initialized in the same manner as the core 99 X input devices. Device-Independent X provides functions that can be 100 called from DDX to initialize these devices. Which functions are called 101 and when will vary by implementation, and will depend on whether the 102 implementation opens all the input devices available to X when X is initialized, 103 or waits until a client requests that a device be opened. 104 In the simplest case, DDX will open all input devices as part of its 105 initialization, when the InitInput routine is called. 106 </para> 107 <sect2 id="Summary_of_Calling_Sequence"> 108 <title>Summary of Calling Sequence</title> 109 <para> 110 <!-- .LP --> 111 <literallayout class="monospaced"> 112 Device-Independent X | Device-Dependent X 113 -------------------- | ------------------- 114 | 115 InitInput --------------> | - do device-specific initialization 116 | 117 | - call AddInputDevice (deviceProc,AutoStart) 118 AddInputDevice | 119 - creates DeviceIntRec | 120 - records deviceProc | 121 - adds new device to | 122 list of off_devices. | 123 sets dev->startup=AutoStart| 124 | - call one of: 125 | - RegisterPointerDevice (X pointer) 126 | - processInputProc = ProcessPointerEvents 127 | - RegisterKeyboardDevice (X keyboard) 128 | - processInputProc = ProcessKeyboardEvents 129 | - RegisterOtherDevice (extension device) 130 | - processInputProc = ProcessOtherEvents 131 | 132 | 133 InitAndStartDevices -----> | - calls deviceProc with parameters 134 | (DEVICE_INIT, AutoStart) 135 sets dev->inited = return | 136 value from deviceProc | 137 | 138 | - in deviceProc, do one of: 139 | - call InitPointerDeviceStruct (X pointer) 140 | - call InitKeyboardDeviceStruct (X keybd) 141 | - init extension device by calling some of: 142 | - InitKeyClassDeviceStruct 143 | - InitButtonClassDeviceStruct 144 | - InitValuatorClassDeviceStruct 145 | - InitValuatorAxisStruct 146 | - InitFocusClassDeviceStruct 147 | - InitProximityClassDeviceStruct 148 | - InitKbdFeedbackClassDeviceStruct 149 | - InitPtrFeedbackClassDeviceStruct 150 | - InitLedFeedbackClassDeviceStruct 151 | - InitStringFeedbackClassDeviceStruct 152 | - InitIntegerFeedbackClassDeviceStruct 153 | - InitBellFeedbackClassDeviceStruct 154 | - init device name and type by: 155 | - calling MakeAtom with one of the 156 | predefined names 157 | - calling AssignTypeAndName 158 | 159 | 160 for each device added | 161 by AddInputDevice, | 162 InitAndStartDevices | 163 calls EnableDevice if | - EnableDevice calls deviceProc with 164 dev->startup & | (DEVICE_ON, AutoStart) 165 dev->inited | 166 | 167 If deviceProc returns | - core devices are now enabled, extension 168 Success, EnableDevice | devices are now available to be accessed 169 move the device from | through the input extension protocol 170 inputInfo.off_devices | requests. 171 to inputInfo.devices | 172 </literallayout> 173 </para> 174 </sect2> 175 <sect2 id="Initialization_Called_From_InitInput"> 176 <title>Initialization Called From InitInput</title> 177 <para> 178 <!-- .LP --> 179 InitInput is the first DDX input entry point called during X server startup. 180 This routine is responsible for 181 device- and implementation- specific initialization, and for calling 182 AddInputDevice to create and initialize the DeviceIntRec structure for each 183 input device. AddInputDevice is passed the address of a procedure to be called 184 by the DIX routine InitAndStartDevices when input devices are enabled. 185 This procedure is expected to perform X initialization for the input device. 186 </para> 187 <para> 188 <!-- .LP --> 189 If the device is to be used as the X pointer, DDX should then call 190 RegisterPointerDevice, passing the DeviceIntRec pointer, 191 to initialize the device as the X pointer. 192 </para> 193 <para> 194 <!-- .LP --> 195 If the device is to be used as the X keyboard, DDX should instead call 196 RegisterKeyboardDevice to initialize the device as the X keyboard. 197 </para> 198 <para> 199 <!-- .LP --> 200 If the device is to be used as an extension device, DDX should instead 201 call RegisterOtherDevice, passing the DeviceIntPtr returned by 202 AddInputDevice. 203 </para> 204 <para> 205 <!-- .LP --> 206 A sample InitInput implementation is shown below. 207 </para> 208 <para> 209 <!-- .LP --> 210 <literallayout class="monospaced"> 211 InitInput(argc,argv) 212 { 213 int i, numdevs; 214 DeviceIntPtr dev; 215 LocalDevice localdevs[LOCAL_MAX_DEVS]; 216 DeviceProc kbdproc, ptrproc, extproc; 217 218 /************************************************************** 219 * Open the appropriate input devices, determine which are 220 * available, and choose an X pointer and X keyboard device 221 * in some implementation-dependent manner. 222 ***************************************************************/ 223 224 open_input_devices (&numdevs, localdevs); 225 226 /************************************************************** 227 * Register the input devices with DIX. 228 ***************************************************************/ 229 230 for (i=0; i<numdevs; i++) 231 { 232 if (localdevs[i].use == IsXKeyboard) 233 { 234 dev = AddInputDevice (kbdproc, TRUE); 235 RegisterKeyboardDevice (dev); 236 } 237 else if (localdevs[i].use == IsXPointer) 238 { 239 dev = AddInputDevice (ptrproc, TRUE); 240 RegisterPointerDevice (dev); 241 } 242 else 243 { 244 dev = AddInputDevice (extproc, FALSE); 245 RegisterOtherDevice (dev); 246 } 247 if (dev == NULL) 248 FatalError ("Too many input devices."); 249 dev->devicePrivate = (pointer) &localdevs[i]; 250 } 251 </literallayout> 252 </para> 253 </sect2> 254 <sect2 id="Initialization_Called_From_InitAndStartDevices"> 255 <title>Initialization Called From InitAndStartDevices</title> 256 <para> 257 <!-- .LP --> 258 After InitInput has returned, 259 InitAndStartDevices is the DIX routine that is called to enable input devices. 260 It calls the device control routine that was passed to AddInputDevice, 261 with a mode value of DEVICE_INIT. The action taken by the device control 262 routine depends on how the device is to be used. If the device is to be 263 the X pointer, the device control routine should call 264 InitPointerDeviceStruct to initialize it. If the device is to be the 265 X keyboard, the device control routine should call 266 InitKeyboardDeviceStruct. Since input extension devices may support various 267 combinations of keys, buttons, valuators, and feedbacks, 268 each class of input that it supports must be initialized. 269 Entry points are defined by DIX to initialize each of the supported classes of 270 input, and are described in the following sections. 271 </para> 272 <para> 273 <!-- .LP --> 274 A sample device control routine called from InitAndStartDevices is 275 shown below. 276 </para> 277 <para> 278 <!-- .LP --> 279 <literallayout class="monospaced"> 280 Bool extproc (dev, mode) 281 DeviceIntPtr dev; 282 int mode; 283 { 284 LocalDevice *localdev = (LocalDevice *) dev->devicePrivate; 285 286 switch (mode) 287 { 288 case DEVICE_INIT: 289 if (strcmp(localdev->name, XI_TABLET) == 0) 290 { 291 /**************************************************** 292 * This device reports proximity, has buttons, 293 * reports two axes of motion, and can be focused. 294 * It also supports the same feedbacks as the X pointer 295 * (acceleration and threshold can be set). 296 ****************************************************/ 297 298 InitButtonClassDeviceStruct (dev, button_count, button_map); 299 InitValuatorClassDeviceStruct (dev, localdev->n_axes,); 300 motionproc, MOTION_BUF_SIZE, Absolute); 301 for (i=0; i<localdev->n_axes; i++) 302 InitValuatorAxisStruct (dev, i, min_val, max_val, 303 resolution); 304 InitFocusClassDeviceStruct (dev); 305 InitProximityClassDeviceStruct (dev); 306 InitPtrFeedbackClassDeviceStruct (dev, p_controlproc); 307 } 308 else if (strcmp(localdev->name, XI_BUTTONBOX) == 0) 309 { 310 /**************************************************** 311 * This device has keys and LEDs, and can be focused. 312 ****************************************************/ 313 314 InitKeyClassDeviceStruct (dev, syms, modmap); 315 InitFocusClassDeviceStruct (dev); 316 InitLedFeedbackClassDeviceStruct (dev, ledcontrol); 317 } 318 else if (strcmp(localdev->name, XI_KNOBBOX) == 0) 319 { 320 /**************************************************** 321 * This device reports motion. 322 * It can be focused. 323 ****************************************************/ 324 325 InitValuatorClassDeviceStruct (dev, localdev->n_axes,); 326 motionproc, MOTION_BUF_SIZE, Absolute); 327 for (i=0; i<localdev->n_axes; i++) 328 InitValuatorAxisStruct (dev, i, min_val, max_val, 329 resolution); 330 InitFocusClassDeviceStruct (dev); 331 } 332 localdev->atom = 333 MakeAtom(localdev->name, strlen(localdev->name), FALSE); 334 AssignTypeAndName (dev, localdev->atom, localdev->name); 335 break; 336 case DEVICE_ON: 337 AddEnabledDevice (localdev->file_ds); 338 dev->on = TRUE; 339 break; 340 case DEVICE_OFF: 341 dev->on = FALSE; 342 RemoveEnabledDevice (localdev->file_ds); 343 break; 344 case DEVICE_CLOSE: 345 break; 346 } 347 } 348 </literallayout> 349 </para> 350 <para> 351 <!-- .LP --> 352 The device control routine is called with a mode value of DEVICE_ON 353 by the DIX routine EnableDevice, which is called from InitAndStartDevices. 354 When called with this mode, it should call AddEnabledDevice to cause the 355 server to begin checking for available input from this device. 356 </para> 357 <para> 358 <!-- .LP --> 359 From InitAndStartDevices, EnableDevice is called for all devices that have 360 the "inited" and "startup" fields in the DeviceIntRec set to TRUE. The 361 "inited" field is set by InitAndStartDevices to the value returned by 362 the deviceproc when called with a mode value of DEVICE_INIT. The "startup" 363 field is set by AddInputDevice to value of the second parameter (autoStart). 364 </para> 365 <para> 366 <!-- .LP --> 367 When the server is first initialized, it should only be checking for input 368 from the core X keyboard and pointer. One way to accomplish this is to 369 call AddInputDevice for the core X keyboard and pointer with an 370 autoStart value equal to TRUE, while calling AddInputDevice for 371 input extension devices with an autoStart value equal to FALSE. If this is 372 done, EnableDevice will skip all input extension devices during server 373 initialization. In this case, 374 the OpenInputDevice routine should set the "startup" field to TRUE 375 when called for input extension devices. This will cause ProcXOpenInputDevice 376 to call EnableDevice for those devices when a client first does an 377 XOpenDevice request. 378 </para> 379 </sect2> 380 <sect2 id="DIX_Input_Class_Initialization_Routines"> 381 <title>DIX Input Class Initialization Routines</title> 382 <para> 383 <!-- .LP --> 384 DIX routines are defined to initialize each of the defined input classes. 385 The defined classes are: 386 <!-- .RS --> 387 <!-- .in +5n --> 388 </para> 389 <itemizedlist> 390 <listitem> 391 <para> 392 KeyClass - the device has keys. 393 </para> 394 </listitem> 395 <listitem> 396 <para> 397 ButtonClass - the device has buttons. 398 </para> 399 </listitem> 400 <listitem> 401 <para> 402 ValuatorClass - the device reports motion data or positional data. 403 </para> 404 </listitem> 405 <listitem> 406 <para> 407 Proximitylass - the device reports proximity information. 408 </para> 409 </listitem> 410 <listitem> 411 <para> 412 FocusClass - the device can be focused. 413 </para> 414 </listitem> 415 <listitem> 416 <para> 417 FeedbackClass - the device supports some kind of feedback. 418 <!-- .in -5n --> 419 <!-- .RE --> 420 </para> 421 </listitem> 422 </itemizedlist> 423 <para> 424 <!-- .LP --> 425 DIX routines are provided to initialize the X pointer and keyboard, as in 426 previous releases of X. During X initialization, InitPointerDeviceStruct 427 is called to initialize the X pointer, and InitKeyboardDeviceStruct is 428 called to initialize the X keyboard. There is no 429 corresponding routine for extension input devices, since they do not all 430 support the same classes of input. Instead, DDX is responsible for the 431 initialization of the input classes supported by extension devices. 432 A description of the routines provided by DIX to perform that initialization 433 follows. 434 </para> 435 <sect3 id="InitKeyClassDeviceStruct"> 436 <title>InitKeyClassDeviceStruct</title> 437 <para> 438 <!-- .LP --> 439 This function is provided to allocate and initialize a KeyClassRec, and 440 should be called for extension devices that have keys. It is passed a pointer 441 to the device, and pointers to arrays of keysyms and modifiers reported by 442 the device. It returns FALSE if the KeyClassRec could not be allocated, 443 or if the maps for the keysyms and modifiers could not be allocated. 444 Its parameters are: 445 </para> 446 <para> 447 <!-- .LP --> 448 <literallayout class="monospaced"> 449 Bool 450 InitKeyClassDeviceStruct(dev, pKeySyms, pModifiers) 451 DeviceIntPtr dev; 452 KeySymsPtr pKeySyms; 453 CARD8 pModifiers[]; 454 </literallayout> 455 </para> 456 <para> 457 <!-- .LP --> 458 The DIX entry point InitKeyboardDeviceStruct calls this routine for the 459 core X keyboard. It must be called explicitly for extension devices 460 that have keys. 461 </para> 462 </sect3> 463 <sect3 id="InitButtonClassDeviceStruct"> 464 <title>InitButtonClassDeviceStruct</title> 465 <para> 466 <!-- .LP --> 467 This function is provided to allocate and initialize a ButtonClassRec, and 468 should be called for extension devices that have buttons. It is passed a 469 pointer to the device, the number of buttons supported, and a map of the 470 reported button codes. It returns FALSE if the ButtonClassRec could not be 471 allocated. Its parameters are: 472 </para> 473 <para> 474 <!-- .LP --> 475 <literallayout class="monospaced"> 476 Bool 477 InitButtonClassDeviceStruct(dev, numButtons, map) 478 register DeviceIntPtr dev; 479 int numButtons; 480 CARD8 *map; 481 </literallayout> 482 </para> 483 <para> 484 <!-- .LP --> 485 The DIX entry point InitPointerDeviceStruct calls this routine for the 486 core X pointer. It must be called explicitly for extension devices that 487 have buttons. 488 </para> 489 </sect3> 490 <sect3 id="InitValuatorClassDeviceStruct"> 491 <title>InitValuatorClassDeviceStruct</title> 492 <para> 493 <!-- .LP --> 494 This function is provided to allocate and initialize a ValuatorClassRec, and 495 should be called for extension devices that have valuators. It is passed the 496 number of axes of motion reported by the device, the address of the motion 497 history procedure for the device, the size of the motion history buffer, 498 and the mode (Absolute or Relative) of the device. It returns FALSE if 499 the ValuatorClassRec could not be allocated. Its parameters are: 500 </para> 501 <para> 502 <!-- .LP --> 503 <literallayout class="monospaced"> 504 Bool 505 InitValuatorClassDeviceStruct(dev, numAxes, motionProc, numMotionEvents, mode) 506 DeviceIntPtr dev; 507 int (*motionProc)(); 508 int numAxes; 509 int numMotionEvents; 510 int mode; 511 </literallayout> 512 </para> 513 <para> 514 <!-- .LP --> 515 The DIX entry point InitPointerDeviceStruct calls this routine for the 516 core X pointer. It must be called explicitly for extension devices that 517 report motion. 518 </para> 519 </sect3> 520 <sect3 id="InitValuatorAxisStruct"> 521 <title>InitValuatorAxisStruct</title> 522 <para> 523 <!-- .LP --> 524 This function is provided to initialize an XAxisInfoRec, and 525 should be called for core and extension devices that have valuators. 526 The space for the XAxisInfoRec is allocated by 527 the InitValuatorClassDeviceStruct function, but is not initialized. 528 </para> 529 <para> 530 <!-- .LP --> 531 InitValuatorAxisStruct should be called once for each axis of motion 532 reported by the device. Each 533 invocation should be passed the axis number (starting with 0), the 534 minimum value for that axis, the maximum value for that axis, and the 535 resolution of the device in counts per meter. If the device reports 536 relative motion, 0 should be reported as the minimum and maximum values. 537 InitValuatorAxisStruct has the following parameters: 538 <literallayout class="monospaced"> 539 InitValuatorAxisStruct(dev, axnum, minval, maxval, resolution) 540 DeviceIntPtr dev; 541 int axnum; 542 int minval; 543 int maxval; 544 int resolution; 545 </literallayout> 546 </para> 547 <para> 548 <!-- .LP --> 549 This routine is not called by InitPointerDeviceStruct for the 550 core X pointer. It must be called explicitly for core and extension devices 551 that report motion. 552 </para> 553 </sect3> 554 <sect3 id="InitFocusClassDeviceStruct"> 555 <title>InitFocusClassDeviceStruct</title> 556 <para> 557 <!-- .LP --> 558 This function is provided to allocate and initialize a FocusClassRec, and 559 should be called for extension devices that can be focused. It is passed a 560 pointer to the device, and returns FALSE if the allocation fails. 561 It has the following parameter: 562 <literallayout class="monospaced"> 563 Bool 564 InitFocusClassDeviceStruct(dev) 565 DeviceIntPtr dev; 566 </literallayout> 567 </para> 568 <para> 569 <!-- .LP --> 570 The DIX entry point InitKeyboardDeviceStruct calls this routine for the 571 core X keyboard. It must be called explicitly for extension devices 572 that can be focused. Whether or not a particular device can be focused 573 is left implementation-dependent. 574 </para> 575 </sect3> 576 <sect3 id="InitProximityClassDeviceStruct"> 577 <title>InitProximityClassDeviceStruct</title> 578 <para> 579 <!-- .LP --> 580 This function is provided to allocate and initialize a ProximityClassRec, and 581 should be called for extension absolute pointing devices that report proximity. 582 It is passed a pointer to the device, and returns FALSE if the allocation fails. 583 It has the following parameter: 584 <literallayout class="monospaced"> 585 Bool 586 InitProximityClassDeviceStruct(dev) 587 DeviceIntPtr dev; 588 </literallayout> 589 </para> 590 </sect3> 591 <sect3 id="Initializing_Feedbacks"> 592 <title>Initializing Feedbacks</title> 593 <para> 594 <!-- .LP --> 595 </para> 596 <sect4 id="InitKbdFeedbackClassDeviceStruct"> 597 <title>InitKbdFeedbackClassDeviceStruct</title> 598 <para> 599 <!-- .LP --> 600 This function is provided to allocate and initialize a KbdFeedbackClassRec, and 601 may be called for extension devices that support some or all of the 602 feedbacks that the core keyboard supports. It is passed a 603 pointer to the device, a pointer to the procedure that sounds the bell, 604 and a pointer to the device control procedure. 605 It returns FALSE if the allocation fails, and has the following parameters: 606 <literallayout class="monospaced"> 607 Bool 608 InitKbdFeedbackClassDeviceStruct(dev, bellProc, controlProc) 609 DeviceIntPtr dev; 610 void (*bellProc)(); 611 void (*controlProc)(); 612 </literallayout> 613 The DIX entry point InitKeyboardDeviceStruct calls this routine for the 614 core X keyboard. It must be called explicitly for extension devices 615 that have the same feedbacks as a keyboard. Some feedbacks, such as LEDs and 616 bell, can be supported either with a KbdFeedbackClass or with BellFeedbackClass 617 and LedFeedbackClass feedbacks. 618 </para> 619 </sect4> 620 <sect4 id="InitPtrFeedbackClassDeviceStruct"> 621 <title>InitPtrFeedbackClassDeviceStruct</title> 622 <para> 623 <!-- .LP --> 624 This function is provided to allocate and initialize a PtrFeedbackClassRec, and 625 should be called for extension devices that allow the setting of acceleration 626 and threshold. It is passed a pointer to the device, 627 and a pointer to the device control procedure. 628 It returns FALSE if the allocation fails, and has the following parameters: 629 <literallayout class="monospaced"> 630 Bool 631 InitPtrFeedbackClassDeviceStruct(dev, controlProc) 632 DeviceIntPtr dev; 633 void (*controlProc)(); 634 </literallayout> 635 </para> 636 <para> 637 <!-- .LP --> 638 The DIX entry point InitPointerDeviceStruct calls this routine for the 639 core X pointer. It must be called explicitly for extension devices 640 that support the setting of acceleration and threshold. 641 </para> 642 </sect4> 643 <sect4 id="InitLedFeedbackClassDeviceStruct"> 644 <title>InitLedFeedbackClassDeviceStruct</title> 645 <para> 646 <!-- .LP --> 647 This function is provided to allocate and initialize a LedFeedbackClassRec, and 648 should be called for extension devices that have LEDs. 649 It is passed a pointer to the device, 650 and a pointer to the device control procedure. 651 It returns FALSE if the allocation fails, and has the following parameters: 652 <literallayout class="monospaced"> 653 Bool 654 InitLedFeedbackClassDeviceStruct(dev, controlProc) 655 DeviceIntPtr dev; 656 void (*controlProc)(); 657 </literallayout> 658 </para> 659 <para> 660 <!-- .LP --> 661 Up to 32 LEDs per feedback can be supported, and a device may have 662 multiple feedbacks of the same type. 663 </para> 664 </sect4> 665 <sect4 id="InitBellFeedbackClassDeviceStruct"> 666 <title>InitBellFeedbackClassDeviceStruct</title> 667 <para> 668 <!-- .LP --> 669 This function is provided to allocate and initialize a BellFeedbackClassRec, 670 and should be called for extension devices that have a bell. 671 It is passed a pointer to the device, 672 and a pointer to the device control procedure. 673 It returns FALSE if the allocation fails, and has the following parameters: 674 <literallayout class="monospaced"> 675 Bool 676 InitBellFeedbackClassDeviceStruct(dev, bellProc, controlProc) 677 DeviceIntPtr dev; 678 void (*bellProc)(); 679 void (*controlProc)(); 680 </literallayout> 681 </para> 682 </sect4> 683 <sect4 id="InitStringFeedbackClassDeviceStruct"> 684 <title>InitStringFeedbackClassDeviceStruct</title> 685 <para> 686 <!-- .LP --> 687 This function is provided to allocate and initialize a StringFeedbackClassRec, 688 and should be called for extension devices that have a display upon which a 689 string can be displayed. 690 It is passed a pointer to the device, 691 and a pointer to the device control procedure. 692 It returns FALSE if the allocation fails, and has the following parameters: 693 <literallayout class="monospaced"> 694 Bool 695 InitStringFeedbackClassDeviceStruct(dev, controlProc, max_symbols, 696 num_symbols_supported, symbols) 697 DeviceIntPtr dev; 698 void (*controlProc)(); 699 int max_symbols; 700 int num_symbols_supported; 701 KeySym *symbols; 702 </literallayout> 703 </para> 704 </sect4> 705 <sect4 id="InitIntegerFeedbackClassDeviceStruct"> 706 <title>InitIntegerFeedbackClassDeviceStruct</title> 707 <para> 708 <!-- .LP --> 709 This function is provided to allocate and initialize an 710 IntegerFeedbackClassRec, 711 and should be called for extension devices that have a display upon which an 712 integer can be displayed. 713 It is passed a pointer to the device, 714 and a pointer to the device control procedure. 715 It returns FALSE if the allocation fails, and has the following parameters: 716 <literallayout class="monospaced"> 717 Bool 718 InitIntegerFeedbackClassDeviceStruct(dev, controlProc) 719 DeviceIntPtr dev; 720 void (*controlProc)(); 721 </literallayout> 722 </para> 723 </sect4> 724 </sect3> 725 </sect2> 726 <sect2 id="Initializing_The_Device_Name_And_Type"> 727 <title>Initializing The Device Name And Type</title> 728 <para> 729 <!-- .LP --> 730 The device name and type can be initialized by calling AssignTypeAndName 731 with the following parameters: 732 <literallayout class="monospaced"> 733 void 734 AssignTypeAndName(dev, type, name) 735 DeviceIntPtr dev; 736 Atom type; 737 char *name; 738 </literallayout> 739 </para> 740 <para> 741 <!-- .LP --> 742 This will allocate space for the device name and copy the name that was passed. 743 The device type can be obtained by calling MakeAtom with one of the names 744 defined for input devices. MakeAtom has the following parameters: 745 <literallayout class="monospaced"> 746 Atom 747 MakeAtom(name, len, makeit) 748 char *name; 749 int len; 750 Bool makeit; 751 </literallayout> 752 </para> 753 <para> 754 <!-- .LP --> 755 Since the atom was already made when the input extension was initialized, the 756 value of makeit should be FALSE; 757 </para> 758 </sect2> 759 </sect1> 760 <sect1 id="Closing_Extension_Devices"> 761 <title>Closing Extension Devices</title> 762 <para> 763 <!-- .LP --> 764 The DisableDevice entry point is provided by DIX to disable input devices. 765 It calls the device control routine for the specified 766 device with a mode value of DEVICE_OFF. The device control routine should 767 call RemoveEnabledDevice to stop the server from checking for input from 768 that device. 769 </para> 770 <para> 771 <!-- .LP --> 772 DisableDevice is not called by any input extension routines. It can be 773 called from the CloseInputDevice routine, which is called by 774 ProcXCloseDevice when a client makes an XCloseDevice request. If 775 DisableDevice is called, it should only be called when the last client 776 using the extension device has terminated or called XCloseDevice. 777 </para> 778 </sect1> 779 <sect1 id="Implementation_Dependent_Routines"> 780 <title>Implementation-Dependent Routines</title> 781 <para> 782 <!-- .LP --> 783 Several input extension protocol requests have 784 implementation-dependent entry points. Default routines 785 are defined for these entry points and contained in the source 786 file extensions/server/xinput/xstubs.c. Some implementations may 787 be able to use the default routines without change. 788 The following sections describe each of these routines. 789 </para> 790 <sect2 id="AddOtherInputDevices"> 791 <title>AddOtherInputDevices</title> 792 <para> 793 <!-- .LP --> 794 AddOtherInputDevice is called from ProcXListInputDevices as a result of 795 an XListInputDevices protocol request. It may be needed by 796 implementations that do not open extension input devices until requested 797 to do so by some client. These implementations may not initialize 798 all devices when the X server starts up, because some of those devices 799 may be in use. Since the XListInputDevices 800 function only lists those devices that have been initialized, 801 AddOtherInputDevices is called to give DDX a chance to 802 initialize any previously unavailable input devices. 803 </para> 804 <para> 805 <!-- .LP --> 806 A sample AddOtherInputDevices routine might look like the following: 807 <literallayout class="monospaced"> 808 void 809 AddOtherInputDevices () 810 { 811 DeviceIntPtr dev; 812 int i; 813 814 for (i=0; i<MAX_DEVICES; i++) 815 { 816 if (!local_dev[i].initialized && available(local_dev[i])) 817 { 818 dev = (DeviceIntPtr) AddInputDevice (local_dev[i].deviceProc, TRUE); 819 dev->public.devicePrivate = local_dev[i]; 820 RegisterOtherDevice (dev); 821 dev->inited = ((*dev->deviceProc)(dev, DEVICE_INIT) == Success); 822 } 823 } 824 } 825 </literallayout> 826 </para> 827 <para> 828 <!-- .LP --> 829 The default AddOtherInputDevices routine in xstubs.c does nothing. 830 If all input extension devices are initialized when the server 831 starts up, it can be left as a null routine. 832 </para> 833 </sect2> 834 <sect2 id="OpenInputDevice"> 835 <title>OpenInputDevice</title> 836 <para> 837 <!-- .LP --> 838 Some X server implementations open all input devices when the server 839 is initialized and never close them. Other implementations may open only 840 the X pointer and keyboard devices during server initialization, 841 and open other input devices only when some client makes an 842 XOpenDevice request. This entry point is for the latter type of 843 implementation. 844 </para> 845 <para> 846 <!-- .LP --> 847 If the physical device is not already open, it can be done in this routine. 848 In this case, the server must keep track of the fact that one or more clients 849 have the device open, and physically close it when the last client that has 850 it open makes an XCloseDevice request. 851 </para> 852 <para> 853 <!-- .LP --> 854 The default implementation is to do nothing (assume all input devices 855 are opened during X server initialization and kept open). 856 </para> 857 </sect2> 858 <sect2 id="CloseInputDevice"> 859 <title>CloseInputDevice</title> 860 <para> 861 <!-- .LP --> 862 Some implementations may close an input device when the last client 863 using that device requests that it be closed, or terminates. 864 CloseInputDevice is called from ProcXCloseDevice when a client 865 makes an XCloseDevice protocol request. 866 </para> 867 <para> 868 <!-- .LP --> 869 The default implementation is to do nothing (assume all input devices 870 are opened during X server initialization and kept open). 871 </para> 872 </sect2> 873 <sect2 id="SetDeviceMode"> 874 <title>SetDeviceMode</title> 875 <para> 876 <!-- .LP --> 877 Some implementations support input devices that can report 878 either absolute positional data or relative motion. The XSetDeviceMode 879 protocol request is provided to allow DDX to change the current mode of 880 such a device. 881 </para> 882 <para> 883 <!-- .LP --> 884 The default implementation is to always return a BadMatch error. If the 885 implementation does not support any input devices that are capable of 886 reporting both relative motion and absolute position information, the 887 default implementation may be left unchanged. 888 </para> 889 </sect2> 890 <sect2 id="SetDeviceValuators"> 891 <title>SetDeviceValuators</title> 892 <para> 893 <!-- .LP --> 894 Some implementations support input devices that allow their valuators to be 895 set to an initial value. The XSetDeviceValuators 896 protocol request is provided to allow DDX to set the valuators of 897 such a device. 898 </para> 899 <para> 900 <!-- .LP --> 901 The default implementation is to always return a BadMatch error. If the 902 implementation does not support any input devices that allow their 903 valuators to be set, the default implementation may be left unchanged. 904 </para> 905 </sect2> 906 <sect2 id="ChangePointerDevice"> 907 <title>ChangePointerDevice</title> 908 <para> 909 <!-- .LP --> 910 The XChangePointerDevice protocol request is provided to change which device is 911 used as the X pointer. Some implementations may maintain information 912 specific to the X pointer in the private data structure pointed to by 913 the DeviceIntRec. ChangePointerDevice is called to allow such 914 implementations to move that information to the new pointer device. 915 The current location of the X cursor is an example of the type of 916 information that might be affected. 917 </para> 918 <para> 919 <!-- .LP --> 920 The DeviceIntRec structure that describes the X pointer device does not 921 contain a FocusRec. If the device that has been made into the new X pointer 922 was previously a device that could be focused, ProcXChangePointerDevice will 923 free the FocusRec associated with that device. 924 </para> 925 <para> 926 <!-- .LP --> 927 If the server implementation desires to allow clients to focus the old pointer 928 device (which is now accessible through the input extension), it should call 929 InitFocusClassDeviceStruct for the old pointer device. 930 </para> 931 <para> 932 <!-- .LP --> 933 The XChangePointerDevice protocol request also allows the client 934 to choose which axes of the new pointer device are used to move 935 the X cursor in the X- and Y- directions. If the axes are different 936 than the default ones, the server implementation should record that fact. 937 </para> 938 <para> 939 <!-- .LP --> 940 If the server implementation supports input devices with valuators that 941 are not allowed to be used as the X pointer, they should be screened out 942 by this routine and a BadDevice error returned. 943 </para> 944 <para> 945 <!-- .LP --> 946 The default implementation is to do nothing. 947 </para> 948 </sect2> 949 <sect2 id="ChangeKeyboardDevice"> 950 <title>ChangeKeyboardDevice</title> 951 <para> 952 <!-- .LP --> 953 The XChangeKeyboardDevice protocol request is provided to change which device is 954 used as the X keyboard. Some implementations may maintain information 955 specific to the X keyboard in the private data structure pointed to by 956 the DeviceIntRec. ChangeKeyboardDevice is called to allow such 957 implementations to move that information to the new keyboard device. 958 </para> 959 <para> 960 <!-- .LP --> 961 The X keyboard device can be focused, and the DeviceIntRec that describes 962 that device has a FocusRec. If the device that has been made into the new X 963 keyboard did not previously have a FocusRec, 964 ProcXChangeKeyboardDevice will allocate one for it. 965 </para> 966 <para> 967 <!-- .LP --> 968 If the implementation does not want clients to be able to focus the old X 969 keyboard (which has now become available as an input extension device) 970 it should call DeleteFocusClassDeviceStruct to free the FocusRec. 971 </para> 972 <para> 973 <!-- .LP --> 974 If the implementation supports input devices with keys that are not allowed 975 to be used as the X keyboard, they should be checked for here, and a 976 BadDevice error returned. 977 </para> 978 <para> 979 <!-- .LP --> 980 The default implementation is to do nothing. 981 </para> 982 </sect2> 983 </sect1> 984 <sect1 id="Input_Extension_Events"> 985 <title>Input Extension Events</title> 986 <para> 987 <!-- .LP --> 988 Events accessed through the input extension are analogous to the core input 989 events, but have different event types. They are of types 990 <function>DeviceKeyPress</function>, <function>DeviceKeyRelease</function>, <function>DeviceButtonPress</function>, 991 <function>DeviceButtonRelease</function>, <function>DeviceDeviceMotionNotify</function>, 992 <function>DeviceProximityIn</function>, <function>DeviceProximityOut</function>, and <function>DeviceValuator</function>. 993 These event types are not constants. Instead, they are external integers 994 defined by the input extension. Their actual values will depend on which 995 extensions are supported by a server, and the order in which they are 996 initialized. 997 </para> 998 <para> 999 <!-- .LP --> 1000 The data structures that describe these 1001 events are defined in the file <function>extensions/include/XIproto.h</function>. Other 1002 input extension constants needed by DDX are defined in the file 1003 <function>extensions/include/XI.h</function>. 1004 </para> 1005 <para> 1006 <!-- .LP --> 1007 Some events defined by the input extension contain more information than can 1008 be contained in the 32-byte xEvent data structure. To send this information 1009 to clients, DDX must generate two or more 32-byte wire events. The following 1010 sections describe the contents of these events. 1011 </para> 1012 <sect2 id="Device_Key_Events"> 1013 <title>Device Key Events</title> 1014 <para> 1015 <!-- .LP --> 1016 <function>DeviceKeyPresss</function> events contain all the information that is contained in 1017 a core <function>KeyPress</function> event, and also the following additional information: 1018 </para> 1019 <para> 1020 <!-- .LP --> 1021 <!-- .RS --> 1022 <!-- .in +5n --> 1023 </para> 1024 <itemizedlist> 1025 <listitem> 1026 <para> 1027 deviceid - the identifier of the device that generated the event. 1028 </para> 1029 </listitem> 1030 <listitem> 1031 <para> 1032 device_state - the state of any modifiers on the device that generated the event. 1033 </para> 1034 </listitem> 1035 <listitem> 1036 <para> 1037 num_valuators - the number of valuators reported in this event. 1038 </para> 1039 </listitem> 1040 <listitem> 1041 <para> 1042 first_valuator - the first valuator reported in this event. 1043 </para> 1044 </listitem> 1045 <listitem> 1046 <para> 1047 valuator0 through valuator5 - the values of the valuators. 1048 <!-- .in -5n --> 1049 <!-- .RE --> 1050 </para> 1051 </listitem> 1052 </itemizedlist> 1053 <para> 1054 <!-- .LP --> 1055 In order to pass this information to the input extension library, two 32-byte 1056 wire events must be generated by DDX. The first has an event type of 1057 <function>DeviceKeyPress</function>, and the second has an event type of <function>DeviceValuator</function>. 1058 </para> 1059 <para> 1060 <!-- .LP --> 1061 The following code fragment shows how the two wire events could be initialized: 1062 </para> 1063 <para> 1064 <!-- .LP --> 1065 <literallayout class="monospaced"> 1066 extern int DeviceKeyPress; 1067 DeviceIntPtr dev; 1068 xEvent xE[2]; 1069 CARD8 id, num_valuators; 1070 INT16 x, y, pointerx, pointery; 1071 Time timestamp; 1072 deviceKeyButtonPointer *xev = (deviceKeyButtonPointer *) xE; 1073 deviceValuator *xv; 1074 1075 xev->type = DeviceKeyPress; /* defined by input extension */ 1076 xev->detail = keycode; /* key pressed on this device */ 1077 xev->time = timestamp; /* same as for core events */ 1078 xev->rootX = pointerx; /* x location of core pointer */ 1079 xev->rootY = pointery; /* y location of core pointer */ 1080 1081 /******************************************************************/ 1082 /* */ 1083 /* The following field does not exist for core input events. */ 1084 /* It contains the device id for the device that generated the */ 1085 /* event, and also indicates whether more than one 32-byte wire */ 1086 /* event is being sent. */ 1087 /* */ 1088 /******************************************************************/ 1089 1090 xev->deviceid = dev->id | MORE_EVENTS; /* sending more than 1 */ 1091 1092 /******************************************************************/ 1093 /* Fields in the second 32-byte wire event: */ 1094 /******************************************************************/ 1095 1096 xv = (deviceValuator *) ++xev; 1097 xv->type = DeviceValuator; /* event type of second event */ 1098 xv->deviceid = dev->id; /* id of this device */ 1099 xv->num_valuators = 0; /* no valuators being sent */ 1100 xv->device_state = 0; /* will be filled in by DIX */ 1101 </literallayout> 1102 </para> 1103 </sect2> 1104 <sect2 id="Device_Button_Events"> 1105 <title>Device Button Events</title> 1106 <para> 1107 <!-- .LP --> 1108 <function>DeviceButton</function> events contain all the information that is contained in 1109 a core button event, and also the same additional information that a 1110 <function>DeviceKey</function> event contains. 1111 </para> 1112 </sect2> 1113 <sect2 id="Device_Motion_Events"> 1114 <title>Device Motion Events</title> 1115 <para> 1116 <!-- .LP --> 1117 <function>DeviceMotion</function> events contain all the information that is contained in 1118 a core motion event, and also additional valuator information. At least 1119 two wire events are required to contain this information. 1120 The following code fragment shows how the two wire events could be initialized: 1121 </para> 1122 <para> 1123 <!-- .LP --> 1124 <literallayout class="monospaced"> 1125 extern int DeviceMotionNotify; 1126 DeviceIntPtr dev; 1127 xEvent xE[2]; 1128 CARD8 id, num_valuators; 1129 INT16 x, y, pointerx, pointery; 1130 Time timestamp; 1131 deviceKeyButtonPointer *xev = (deviceKeyButtonPointer *) xE; 1132 deviceValuator *xv; 1133 1134 xev->type = DeviceMotionNotify; /* defined by input extension */ 1135 xev->detail = keycode; /* key pressed on this device */ 1136 xev->time = timestamp; /* same as for core events */ 1137 xev->rootX = pointerx; /* x location of core pointer */ 1138 xev->rootY = pointery; /* y location of core pointer */ 1139 1140 /******************************************************************/ 1141 /* */ 1142 /* The following field does not exist for core input events. */ 1143 /* It contains the device id for the device that generated the */ 1144 /* event, and also indicates whether more than one 32-byte wire */ 1145 /* event is being sent. */ 1146 /* */ 1147 /******************************************************************/ 1148 1149 xev->deviceid = dev->id | MORE_EVENTS; /* sending more than 1 */ 1150 1151 /******************************************************************/ 1152 /* Fields in the second 32-byte wire event: */ 1153 /******************************************************************/ 1154 1155 xv = (deviceValuator *) ++xev; 1156 xv->type = DeviceValuator; /* event type of second event */ 1157 xv->deviceid = dev->id; /* id of this device */ 1158 xv->num_valuators = 2; /* 2 valuators being sent */ 1159 xv->first_valuator = 0; /* first valuator being sent */ 1160 xv->device_state = 0; /* will be filled in by DIX */ 1161 xv->valuator0 = x; /* first axis of this device */ 1162 xv->valuator1 = y; /* second axis of this device */ 1163 </literallayout> 1164 </para> 1165 <para> 1166 <!-- .LP --> 1167 Up to six axes can be reported in the deviceValuator event. If the device 1168 is reporting more than 6 axes, additional pairs of DeviceMotionNotify and 1169 DeviceValuator events should be sent, with the first_valuator field 1170 set correctly. 1171 </para> 1172 </sect2> 1173 <sect2 id="Device_Proximity_Events"> 1174 <title>Device Proximity Events</title> 1175 <para> 1176 <!-- .LP --> 1177 Some input devices that report absolute positional information, such as 1178 graphics tablets and touchscreens, may report proximity events. 1179 <function>ProximityIn</function> 1180 events are generated when a pointing device like a stylus, or in the case 1181 of a touchscreen, the user's finger, comes into close proximity with the 1182 surface of the input device. <function>ProximityOut</function> events are generated when 1183 the stylus or finger leaves the proximity of the input devices surface. 1184 </para> 1185 <para> 1186 <!-- .LP --> 1187 <function>Proximity</function> events contain almost the same information as button events. 1188 The event type is <function>ProximityIn</function> or <function>ProximityOut</function>, and there is no 1189 detail information. 1190 <!-- .bp --> 1191 <!-- .\" .TC --> 1192 1193 </para> 1194 </sect2> 1195 </sect1> 1196 </chapter> 1197 </book>